ABSTRACT The Antibody and BioResource (ABR) Core is a vibrant facility that contributes broadly to the basic and translational mission of the Center by focusing on two tools central to reproducibile research, specifically antibodies and cell lines. The Core works with researchers to develop new monoclonal antibodies (MAbs) against their target(s) of interest that will work in the required application(s). When antibodies are not readily available elsewhere, particularly newly developed at MSK, the facility provides access to essential MAbs by: 1) Producing (in vitro); 2) Purifying; 3) Conjugating (to fluorphores and proteins); and/or 4) Fragmenting them into Fab or F(Ab?)2 fragments. To promote the use of healthy cell cultures, which is central to generating reproducable data from these in vitro systems, the ABR Core offers a mycoplasma testing service. Well authenticated cell lines created at MSK and deposited into the Core are distributed to researchers around the world, which ensures the tools that the Cancer Center is sharing are of the highest quality. Relevant information and testing results on curated cell lines are also shared with recipients. These include, but are not limited to, a description and history of the line, references, culture conditions, unique characteristics, STR profiles for authentication purposes of human cell lines, images of the cells, confirmation that no mycoplasma was detectable in the culture, karyotyping, and appropriate flow cytometric analysis. During the past grant period the ABR Core has contributed to 50 publications for researchers from seven of the 10 CCSG Programs.